Nutrition & Supplements

Omega-3 Fatty Acids

Polyunsaturated fatty acids (EPA, DHA, ALA) with anti-inflammatory properties. In dogs, marine-sourced EPA and DHA are the biologically active forms supporting joint, cardiac, cognitive, and skin health.

Omega-3 fatty acids are a family of polyunsaturated fatty acids characterized by a double bond at the third carbon position from the methyl end. The three primary omega-3s of nutritional relevance are:

  • ALA (alpha-linolenic acid): plant-derived (flaxseed, chia); not directly bioactive in dogs
  • EPA (eicosapentaenoic acid): marine-sourced; primary anti-inflammatory omega-3 in dogs
  • DHA (docosahexaenoic acid): marine-sourced; critical for brain and retinal function; anti-inflammatory

Dogs convert ALA to EPA and DHA at very low efficiency (<15%). Marine-sourced omega-3s (fish oil, algae oil) are the appropriate supplementation form.

Evidence-Based Benefits in Dogs

Joint disease (OA): Multiple randomized controlled trials show fish oil supplementation at 75–100 mg EPA+DHA/kg/day reduces lameness scores and owner-reported pain in dogs with osteoarthritis. Evidence quality: moderate-high.

Atopic dermatitis (skin allergies): Omega-3 supplementation reduces skin inflammation and pruritus scores. Often used adjunctively with other allergy management. Evidence: moderate.

Cardiac disease: Omega-3s have anti-arrhythmic properties and may slow myocardial disease progression. The ACVIM and cardiology specialists recommend omega-3 supplementation in dogs with DCM and chronic valvular disease.

Cognitive dysfunction: DHA is a structural component of neuronal membranes. Supplementation in senior dogs shows modest improvement in cognitive function scores. Evidence: preliminary.

Kidney disease: EPA and DHA reduce glomerular hypertension and proteinuria. Recommended as adjunctive therapy in CKD.

Dosing

Veterinary guidelines suggest 75–100 mg EPA+DHA per kg body weight per day for anti-inflammatory effect. This is significantly higher than most pet-labeled fish oil products provide at label dose.

Practical calculation: a 30 kg dog requires 2,250–3,000 mg EPA+DHA daily. A standard 1,000 mg fish oil capsule contains approximately 180 mg EPA + 120 mg DHA = 300 mg total omega-3, requiring 7–10 capsules/day. High-concentration fish oil products provide 500–800 mg EPA+DHA per capsule.

Quality Considerations

Fish oil quality varies significantly. Key considerations:

  • Oxidation: rancid fish oil is ineffective and potentially harmful; smell-test; store refrigerated after opening
  • Contaminants: heavy metals in low-quality fish oil; choose molecularly distilled or NSF/IFOS-certified products
  • Species source: sardine/anchovy/mackerel oil (small, short-lived fish) have lower heavy metal burden than cod or tuna